Impedance relay performance improvement method and device

Abstract

The invention provides an impedance relay performance improvement method and device, and relates to the field of power system maintenance, and the method comprises the steps: building an arc model according to the dynamic characteristics of a fault arc when a power grid has a grounding fault; calculating fault impedance according to the grounding fault type of the fault arc, the electrical parameters at the phase source after the fault and the arc model; determining an action threshold value for executing circuit breaking processing according to the arc model; and enabling an impedance relay to carry out distance protection on a power grid according to the action threshold value and the fault impedance. According to the impedance relay performance improvement method and device, the action threshold value of the impedance relay executing the circuit breaking processing can be determined, and the performance of the impedance relay is improved.

Description

Technical Field

[0001] This application relates to the field of power equipment maintenance, and specifically to a method and device for improving the performance of impedance relays. Background Art

[0002] When an electrical fault occurs in a transmission line, the primary goal is to ensure the stability of the network. Developing a protection system that is both fast and highly reliable must meet these basic requirements. Distance protection relays are specifically designed to detect faults occurring in high-voltage transmission lines and locate the faults. The distance relay continuously calculates the line impedance by measuring the voltage measurement value and current measurement value obtained from the transformer. This type of relay relies on the impedance percentage and can locate the fault and clear the fault in a timely manner.

[0003] When an electrical fault occurs on the line, an arc is generated, and its resistance affects the fault location and may cause improper operation of the distance relay. Currently, the most widely used method for locating the fault position of an overhead line is to determine the apparent reactance of the line during the flow of fault current and convert the ohmic result to distance based on the line parameters. It is generally recognized that this method introduces errors when the fault resistance is high and the line is powered from both ends.

[0004] Currently, distance protection calculates the fault impedance by using the voltage and current at the relay installation location. The recorded fault impedance is compared with the known line impedance. If the recorded fault impedance is less than the predetermined line impedance, the fault is identified and a trip signal is sent to the circuit breaker. In its most basic form, distance protection only relies on measuring voltage and current without supplementary information or external devices.

[0005] However, due to measurement errors, transformer errors (CT, PT), and changes in line impedance, it is actually impossible to achieve 100% distance protection accuracy for the entire line length. Therefore, a safety margin of 10% to 15% is established from the line end, called the reach-down zone (also known as the first zone), to ensure the protection selectivity for internal and external faults.

[0006] The remaining line portion belongs to the over-reach zone (also known as the second zone). To maintain selectivity, a time delay needs to be set corresponding to the adjacent protection scheme. In electromagnetic protection, this time delay is usually between 400 - 500 milliseconds, while analog static and digital protection systems achieve a delay of 250 - 300 milliseconds. This delay includes the operating time of the circuit breaker, the response time of the distance measurement element, and the safety margin.

[0007] Different from differential protection, which achieves complete selectivity by considering the positions of current transformers at both ends of a line, basic distance protection (without communication enhancement) does not provide complete selectivity and achieves selective tripping through coordination with the time delays of adjacent protection schemes. Nevertheless, distance protection can be used as a backup protection for adjacent lines, using the second stage (overreach stage), which extends to adjacent buses and a part of adjacent lines. There is also a third stage, which is usually deployed to protect the entire length of adjacent lines. The arrangement of these stages and their time settings are determined using a time-distance diagram.

[0008] Traditional ground distance relay schemes face challenges in dealing with various types of ground faults, such as single-phase ground and double-phase ground faults. These challenges are exacerbated by significant fault resistance.

[0009] This section aims to provide background or context for the embodiments of the present invention stated in the claims. The description herein is not admitted to be prior art merely because it is included in this section. Summary of the Invention

[0010] In view of the problems in the prior art, the present application provides a method and device for improving the performance of an impedance relay, which can determine the action threshold value for the impedance relay to perform a breaking process and improve the performance of the impedance relay.

[0011] To solve the above technical problems, the present application provides the following technical solutions:

[0012] In a first aspect, the present application provides a method for improving the performance of an impedance relay, including:

[0013] When a ground fault occurs in the power grid, an arc model is constructed according to the dynamic characteristics of the fault arc;

[0014] The fault impedance is calculated according to the type of the ground fault of the fault arc, the electrical parameters at the phase source after the fault, and the arc model;

[0015] The action threshold value for performing a breaking process is determined according to the arc model;

[0016] The impedance relay performs distance protection on the power grid according to the action threshold value and the fault impedance.

[0017] Further, the arc model includes a main arc model and a secondary arc model; when a ground fault occurs in the power grid, constructing the arc model according to the dynamic characteristics of the fault arc includes:

[0018] The main arc model is determined according to the characteristic arc voltage gradient, the total characteristic arc resistance, and the instantaneous arc length when a ground fault occurs in the power grid;

[0019] Determine the secondary arc model according to the arc elongation speed, initial time constant and time constant decline speed when a grounding fault occurs in the power grid.

[0020] Further, the grounding fault type includes single-phase grounding fault; the electrical parameters include the current at the phase source after the fault, the voltage at the phase source after the fault, and the grounding coefficient; the calculating of the fault impedance according to the grounding fault type of the fault arc, the electrical parameters at the phase source after the fault, and the arc model includes:

[0021] Generate an arc additional impedance according to the arc model;

[0022] Calculate a first fault current according to the grounding coefficient and the current at the phase source after the fault;

[0023] Calculate the fault impedance when the single-phase grounding fault occurs according to the first fault current, the voltage at the phase source after the fault, and the arc additional impedance.

[0024] Further, the grounding fault type includes double-phase grounding fault; the electrical parameters include the current at the phase source after the fault and the voltage at the phase source after the fault; the calculating of the fault impedance according to the grounding fault type of the fault arc, the electrical parameters at the phase source after the fault, and the arc model includes:

[0025] Generate an arc additional impedance according to the arc model;

[0026] Calculate a second fault current according to the current at the phase source after the fault;

[0027] Calculate the fault impedance when the double-phase grounding fault occurs according to the second fault current, the voltage at the phase source after the fault, and the arc additional impedance.

[0028] Further, the determining of the action threshold value for the impedance relay to perform the open-circuit processing according to the arc model and the fault impedance includes:

[0029] Obtain an initial action threshold value based on the dynamic characteristics of the arc;

[0030] Adjust the initial action threshold value according to the arc model to obtain the action threshold value for the impedance relay to perform the open-circuit processing.

[0031] In a second aspect, the present application provides an impedance relay performance improvement device, including:

[0032] An arc model construction unit, configured to construct an arc model according to the dynamic characteristics of the fault arc when a grounding fault occurs in the power grid;

[0033] A fault impedance calculation unit, configured to calculate the fault impedance according to the grounding fault type of the fault arc, the electrical parameters at the phase source after the fault, and the arc model;

[0034] An action threshold determination unit, configured to determine the action threshold value for performing the open circuit process according to the arc model;

[0035] A distance protection execution unit, configured to perform distance protection on the power grid by an impedance relay according to the action threshold value and the fault impedance.

[0036] Further, the arc model includes a main arc model and a secondary arc model; the arc model construction unit includes:

[0037] A main arc model determination module, configured to determine the main arc model according to the characteristic arc voltage gradient, the total characteristic arc resistance, and the instantaneous arc length when a grounding fault occurs in the power grid;

[0038] A secondary arc model determination module, configured to determine the secondary arc model according to the arc elongation speed, the initial time constant, and the time constant decay speed when a grounding fault occurs in the power grid.

[0039] Further, the grounding fault type includes a single-phase grounding fault; the electrical parameters include the current at the phase source after the fault, the voltage at the phase source after the fault, and the grounding coefficient; the fault impedance calculation unit includes:

[0040] A first additional impedance generation module, configured to generate an arc additional impedance according to the arc model;

[0041] A first fault current calculation module, configured to calculate a first fault current according to the grounding coefficient and the current at the phase source after the fault;

[0042] A first fault impedance calculation module, configured to calculate the fault impedance when the single-phase grounding fault occurs according to the first fault current, the voltage at the phase source after the fault, and the arc additional impedance.

[0043] Further, the grounding fault type includes a double-phase grounding fault; the electrical parameters include the current at the phase source after the fault and the voltage at the phase source after the fault; the fault impedance calculation unit includes:

[0044] A second additional impedance generation module, configured to generate an arc additional impedance according to the arc model;

[0045] A second fault current calculation module, configured to calculate a second fault current according to the current at the phase source after the fault;

[0046] A second fault impedance calculation module, configured to calculate the fault impedance when the double-phase grounding fault occurs according to the second fault current, the voltage at the post-fault phase source, and the arc additional impedance.

[0047] Further, the action threshold determination unit includes:

[0048] An initial threshold value acquisition module, configured to acquire an initial action threshold value based on the dynamic characteristics of the arc;

[0049] An action threshold value determination module, configured to adjust the initial action threshold value according to the arc model to obtain the action threshold value for the impedance relay to perform the open-circuit processing.

[0050] In a third aspect, the present application provides an electronic device including a memory, a processor, and a computer program stored on the memory and executable on the processor. When the processor executes the program, the steps of the method for improving the performance of the impedance relay are implemented.

[0051] In a fourth aspect, the present application provides a computer-readable storage medium, on which a computer program is stored. When the computer program is executed by a processor, the steps of the method for improving the performance of the impedance relay are implemented.

[0052] In a fifth aspect, the present application provides a computer program product, including a computer program / instructions. When the computer program / instructions are executed by a processor, the steps of the method for improving the performance of the impedance relay are implemented.

[0053] Regarding the problems in the prior art, the method and device for improving the performance of the impedance relay provided by the present application, by constructing an arc model according to the dynamic characteristics of the fault arc when a grounding fault occurs in the power grid; calculating the fault impedance according to the grounding fault type of the fault arc, the electrical parameters at the post-fault phase source, and the arc model; determining the action threshold value for performing the open-circuit processing according to the arc model; and enabling the impedance relay to perform distance protection on the power grid according to the action threshold value and the fault impedance, improve the accuracy of the impedance relay in sensing and calculating the fault impedance, improve the modeling and estimation accuracy of the arc resistance, and highlight the importance of the impedance relay in detecting and locating faults in high-voltage power networks. In addition, the present application simulates two types of faults and calculates the arc resistance, providing valuable technical basis for the performance of the impedance relay under different configurations. Based on the above technical basis, the high-voltage power network can be better protected from the threat of fault arcs. Description of the Drawings

[0054] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the accompanying drawings required for use in the description of the embodiments or the prior art. Obviously, the accompanying drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other accompanying drawings can be obtained based on these drawings.

[0055] Figure 1 It is a schematic flowchart of a method for improving the performance of an impedance relay provided by an embodiment of the present application;

[0056] Figure 2 It is a schematic flowchart of a method for improving the performance of an impedance relay provided by an embodiment of the present application;

[0057] Figure 3 It is a schematic flowchart of a method for improving the performance of an impedance relay provided by an embodiment of the present application;

[0058] Figure 4 It is a schematic flowchart of a method for improving the performance of an impedance relay provided by an embodiment of the present application;

[0059] Figure 5 It is a schematic flowchart of a method for improving the performance of an impedance relay provided by an embodiment of the present application;

[0060] Figure 6 It is a schematic structural diagram of a device for improving the performance of an impedance relay provided by an embodiment of the present application;

[0061] Figure 7 It is a schematic structural diagram of a device for improving the performance of an impedance relay provided by an embodiment of the present application;

[0062] Figure 8 It is a schematic structural diagram of a device for improving the performance of an impedance relay provided by an embodiment of the present application;

[0063] Figure 9 It is a schematic structural diagram of a device for improving the performance of an impedance relay provided by an embodiment of the present application;

[0064] Figure 10 It is a schematic structural diagram of a device for improving the performance of an impedance relay provided by an embodiment of the present application;

[0065] Figure 11 It is a schematic structural diagram of an electronic device provided by an embodiment of the present application;

[0066] Figure 12 It is an equivalent circuit diagram of an arc fault provided by an embodiment of the present application;

[0067] Figure 13It is a schematic diagram showing the change from an old operating impedance circle to a new operating impedance circle provided by an embodiment of the present application. Detailed implementation manners

[0068] To make the objectives, technical solutions and advantages of the embodiments of the present application clearer and more understandable, the embodiments of the present application will be further described in detail below with reference to the accompanying drawings. Herein, the illustrative embodiments of the present application and their descriptions are used to explain the present application, but do not limit the present application. It should be noted that, without conflict, the embodiments in the present application and the features in the embodiments can be combined arbitrarily with each other.

[0069] Taking the server as the execution entity as an example below, the specific implementation process of the impedance relay performance improvement method provided by the embodiments of the present application will be described.

[0070] Figure 1 It is a flowchart of the impedance relay performance improvement method provided by an embodiment of the present application. As Figure 1 shown, in order to be able to determine the action threshold value for the impedance relay to perform the open circuit processing and improve the performance of the impedance relay, the impedance relay performance improvement method provided by the present application includes:

[0071] S101: When a ground fault occurs in the power grid, an arc model is constructed according to the dynamic characteristics of the fault arc;

[0072] S102: Calculate the fault impedance according to the ground fault type of the fault arc, the electrical parameters at the phase source after the fault, and the arc model;

[0073] S103: Determine the action threshold value for performing the open circuit processing according to the arc model;

[0074] S104: Perform distance protection on the power grid by the impedance relay according to the action threshold value and the fault impedance.

[0075] From Figure 1 the shown process, it can be seen that the present application provides an impedance relay performance improvement method. When a ground fault occurs in the power grid, an arc model is constructed according to the dynamic characteristics of the fault arc; the fault impedance is calculated according to the ground fault type of the fault arc, the electrical parameters at the phase source after the fault, and the arc model; the action threshold value for performing the open circuit processing is determined according to the arc model; distance protection is performed on the power grid by the impedance relay according to the action threshold value and the fault impedance, so as to improve the accuracy of the impedance relay in sensing and calculating the fault impedance, improve the modeling and estimation accuracy of the arc resistance, and highlight the importance of the impedance relay in detecting and locating faults in high-voltage power networks.

[0076] Each step will be explained in detail below.

[0077] S101: When a grounding fault occurs in the power grid, an arc model is constructed according to the dynamic characteristics of the fault arc;

[0078] Specifically, when a grounding fault occurs, by real-time monitoring the dynamic characteristics of the arc, the server uses the differential equation of arc conductivity to describe the evolution of arc conductivity, differentiating the main arc stage (the arc length and time constant are basically constant) in the initial stage of the fault and the secondary arc stage (the arc length linearly increases with time and the time constant gradually decreases) during the continuous fault, thereby constructing a model that reflects the change characteristics of the arc additional impedance.

[0079] Figure 2 It is a schematic flowchart of a method for improving the performance of an impedance relay provided by an embodiment of the present application. The arc model includes a main arc model and a secondary arc model; as Figure 2 shown, S101 includes:

[0080] S201: Determine the main arc model according to the characteristic arc voltage gradient, total characteristic arc resistance and instantaneous arc length when a grounding fault occurs in the power grid;

[0081] Specifically, the fault arc can be regarded as a resistive element connecting the faulty transmission line to the ground. The simplest arc model can be represented as the short-circuit resistance between the transmission line and the ground. However, since the arc continuously and non-linearly extends during its existence, the arc exhibits a non-linearly increasing resistance value. This means that the arc voltage also exhibits a non-linearly increasing trend during the existence of the arc.

[0082] The server applies the extended theory of switching arcs to simulate the unrestricted fault arcs in the air. Both the main arc and the secondary arc are described using the differential equation of arc conduction.

[0083]

[0084] Among them, G represents the static arc conductivity, g represents the arc conductivity varying with time, and τ represents the time parameter (time constant) of the arc.

[0085] The static arc conductivity is the arc conductivity when the arc current remains constant for a long enough time under unchanged external conditions. Therefore, the static arc conductivity G is expressed as follows:

[0086]

[0087] u st (i, l) = (|u0 + r0|) · l arc (t) (3)

[0088]

[0089] Among them, u stis the static arc voltage, representing the arc voltage gradient. u represents the total characteristic arc voltage, measured in volts (V), while r represents the total characteristic arc resistance, in milliohms (mΩ). u0 represents the characteristic arc voltage per unit arc length, measured in volts per centimeter (V / cm), and r0 represents the characteristic arc resistance per unit arc length, in milliohms per centimeter (mΩ / cm). l arc represents the instantaneous arc length, in centimeters (cm), and l0 is the initial length of the arc column, usually referred to as the main arc length, also in centimeters (cm).

[0090] In the main arc model, the arc length l arc and the time parameter τ are relatively constant. In this case, the arc length is represented by the gap length (l0) of the arc angle, and the characteristic arc voltage gradient u0 and the arc resistance per unit length r0 at this time are given by formulas (5) and (6). Therefore, the static arc voltage u st of the main arc is:

[0091] u st = (|u0 + r0|) · l0 (7)

[0092] Based on the static arc voltage u st of the main arc, the arc conductivity in the static state can be obtained:

[0093]

[0094] In the main arc model, since l arc and the time constant τ both remain unchanged (τ depends on the initial conditions), the entire arc is equivalent to a fixed-parameter model. This model describes the conductive characteristics when the arc current reaches a steady state at the initial stage of the fault.

[0095] In one embodiment, the equivalent circuit diagram of the arc fault is as Figure 12 shown.

[0096] S202: Determine the secondary arc model according to the arc elongation speed, initial time constant, and time constant decline speed when a grounding fault occurs in the power grid.

[0097] Specifically, during the fault duration, that is, in the secondary arc current, the arc will elongate, and the arc length and time parameter will change dynamically with time, as follows:

[0098] l arc = (v l · t + 1) · l0 (9)

[0099] τ = τ0 - v τ (l arc - l0) (10)

[0100] wherein, v l is the arc elongation speed, expressed in centimeters per millisecond (cm / ms), τ0 is the initial time constant, expressed in milliseconds (ms), and v τ is the time constant decrease speed, expressed in milliseconds per centimeter (ms / cm).

[0101] According to the above formula, the arc length exhibits a linear growth pattern at the beginning of the secondary arc stage. On the contrary, the time constant is inversely proportional to the arc length. As the arc elongates, the time constant of the arc decreases, thereby affecting the evolution of the arc conductivity.

[0102] The secondary arc stage still follows the differential equation, but at this time the static arc conductivity G is not a constant, but changes with l arc as follows:

[0103]

[0104] As l arc (t) increases, u st (t) also increases accordingly, resulting in a corresponding change in G(t).

[0105] S102: Calculate the fault impedance according to the grounding fault type of the fault arc, the electrical parameters at the phase source after the fault, and the arc model;

[0106] Specifically, based on the constructed arc model, the server combines the grounding fault type corresponding to the fault arc and the electrical parameters measured at the phase source after the fault, and uses a modified impedance calculation formula for calculation. The arc model provides compensation information for the arc additional impedance, making the calculated fault impedance closer to the actual line impedance, thereby more accurately reflecting the location of the fault point.

[0107] Figure 3 is a schematic flowchart of a method for improving the performance of an impedance relay provided by an embodiment of the present application. The grounding fault type includes single-phase grounding fault; the electrical parameters include the current at the phase source after the fault, the voltage at the phase source after the fault, and the grounding coefficient; as Figure 3 shown, S102 includes:

[0108] S301: Generate an arc additional impedance according to the arc model;

[0109] Specifically, the server obtains the arc conductivity according to the arc model and generates an arc additional impedance. The arc additional impedance is expressed as follows:

[0110]

[0111] S302: Calculate the first fault current based on the grounding coefficient and the current at the phase source after the fault;

[0112] Specifically, when the grounding fault type includes single-phase grounding fault, for a single-phase fault in phase 'a', the single-phase fault current can be expressed as:

[0113] I K1 = I Ka + K0·I r (13)

[0114] where, I Ka represents the current of the fault phase (phase A); K0 represents the grounding coefficient; I r represents the residual current, which is equal to the sum of the three-phase currents:

[0115] I r = l Ka + l Kb + l Kc (14)

[0116] S303: Calculate the fault impedance when the single-phase grounding fault occurs based on the first fault current, the voltage at the phase source after the fault, and the arc additional impedance.

[0117] Specifically, since the fault arc introduces additional impedance in the fault loop, it will reduce the measured fault current, resulting in a higher apparent fault impedance calculated by the traditional method. Therefore, the arc additional impedance is used as a correction term for compensation. Subtract the arc additional impedance Z arc (t) from the apparent fault impedance to obtain the corrected fault impedance:

[0118]

[0119] where, U K1 is the voltage at the phase source after the single-phase fault:

[0120] U K1 = V Ka (16)

[0121] Figure 4 is a schematic flow diagram of a method for improving the performance of an impedance relay provided by an embodiment of the present application. The grounding fault type includes double-phase grounding fault; the electrical parameters include the current at the phase source after the fault and the voltage at the phase source after the fault; as Figure 4 shown, S102 includes:

[0122] S401: Generate the arc additional impedance according to the arc model;

[0123] Specifically, the server obtains the arc conductivity based on the arc model and generates an arc additional impedance, and the arc additional impedance is expressed as follows:

[0124]

[0125] S402: Calculate a second fault current according to the current at the phase source after the fault;

[0126] Specifically, when the grounding fault type includes a double-phase grounding fault, for the double-phase grounding fault in phase 'a-b-g', the double-phase fault current can be expressed as:

[0127] I K2 =I Ka -I Kb (17)

[0128] Wherein, I Ka and I Kb represent the currents of the fault phases.

[0129] S403: Calculate the fault impedance when the double-phase grounding fault occurs according to the second fault current, the voltage at the phase source after the fault, and the arc additional impedance.

[0130] Specifically, since the fault arc introduces an additional impedance in the fault loop, it will reduce the measured fault current, resulting in a higher apparent fault impedance calculated conventionally. Therefore, the arc additional impedance is used as a correction term for compensation. Subtracting the arc additional impedance Z arc (t) from the apparent fault impedance to obtain the corrected fault impedance:

[0131]

[0132] Wherein, U K is the voltage at the phase source after the double-phase fault:

[0133] U K2 =V Ka -V Kb (19)

[0134] S103: Determine the action threshold value for performing the open-circuit processing according to the arc model;

[0135] Specifically, the server dynamically adjusts the action threshold value of the relay for open-circuit processing by using the arc additional impedance information extracted from the arc model. By compensating and matching the initial threshold value with the arc additional impedance, it is ensured that when the relay operates, it can effectively filter the errors caused by the arc effect and accurately respond to the real fault impedance, thereby improving the selectivity and reliability of the protection.

[0136] Figure 5It is a schematic flowchart of a method for improving the performance of an impedance relay provided by an embodiment of the present application. As Figure 5 shown, S103 includes:

[0137] S501: Obtain an initial operating threshold based on the dynamic characteristics of the arc;

[0138] Specifically, in order to ensure that the impedance relay can operate correctly under different fault scenarios, the circuit breaker handling threshold of the relay also needs to be dynamically adjusted according to the arc additional impedance. The server pre-determines the initial operating threshold of the relay as Z0 based on system design or historical data.

[0139] S502: Adjust the initial operating threshold according to the arc model to obtain the operating threshold for the impedance relay to perform circuit breaker handling.

[0140] Specifically, the main arc model adds an operating threshold based on the fault impedance, that is, it reduces the misoperation of the impedance relay caused by the fault arc, making the distance calculation value of the fault line more accurate. The fault impedance needs to fall within the operating impedance circle to operate; however, in the calculation of the fault impedance, due to the influence of the arc resistance, a fault that should operate but actually does not operate, resulting in an error.

[0141] Therefore, considering the main arc model, the impedance operating circle is corrected, the influence of the arc resistance is added to the operating threshold of the impedance relay, and in combination with the arc model, the initial threshold is adjusted to include the compensation of the arc additional impedance to obtain the corrected operating threshold Z:

[0142] Z = Z0 + Z arc (t) (20)

[0143] S104: Make the impedance relay perform distance protection on the power grid according to the operating threshold and the fault impedance.

[0144] Specifically, the server compares the fault impedance corrected by the arc model with the adjusted operating threshold. When the corrected fault impedance is lower than the operating threshold, that is, Z′ F < Z, the impedance relay triggers circuit breaker handling to achieve distance protection of the power grid, ensuring that when a fault occurs, the impedance relay can quickly and accurately perform protection actions based on the actual fault distance.

[0145] In one embodiment, based on the power system simulation model, a high-voltage doubly-fed transmission network was constructed using a simulation tool. The network contains two interconnected lines. The line to be protected is connected to the adjacent line, and the line length and parameters are set according to the typical high-voltage transmission system. Three protection zones were defined in the simulation: Zone 1 covers the main part of the main line; Zone 2 covers the entire main line and a partial range of the adjacent line; Zone 3 covers the entire main line and a larger range of the adjacent line. Single-phase and two-phase ground faults were applied at different positions inside and outside the protection zones, including: the proximal and middle sections of the main line in Zone 1; the end of the main line and the starting section of the adjacent line in Zone 2; the middle section of the adjacent line in Zone 3.

[0146] The positive and zero-sequence parameters (including resistance, reactance, and capacitance) of the transmission line were set according to the industry standard model. Two arc models were introduced in the simulation to represent fault arcs with different dynamic characteristics, and their key parameters cover arc length, initial voltage, resistance characteristics, and time constant, etc. The simulation considered the influence of different ground resistance conditions and assumed that the arc length remained stable within a certain range.

[0147] To optimize the operating characteristics of the relay, an adjustment strategy for the operating impedance circle was introduced. According to the line impedance distribution and arc fault characteristics, the impedance circle boundary of each protection zone was dynamically adjusted to ensure that the coverage range of the operating group matches the actual fault location more accurately in the case of high-resistance faults or complex arc scenarios. A dynamic change model of arc resistance was incorporated into the impedance circle decision logic. By real-time correcting the calculated value of the apparent impedance, the operating delay or misjudgment caused by the non-linear characteristics of the arc was reduced. Through the overlapping design of impedance circles between regions, the coordination between the main protection and the backup protection was enhanced, and the cascaded misoperation of the protection logic was avoided when a single region fails.

[0148] Compare the responses of the relay under different fault scenarios. In the case of a single-phase fault, the increase in arc parameters (such as resistance and voltage) will cause a significant increase in the fault impedance calculated by the relay, and the farther the fault point is from the power source, the more obvious the influence of the linear impedance. The operating impedance circle strategy effectively suppresses the impedance drift under high-resistance faults, making the judgment of the relay at the zone boundary more accurate. The high ground resistance further restricts the fault current, but through the dynamic adjustment of the anti-circle logic, the error amplitude is significantly reduced. In the case of a two-phase ground fault, the influence of arc parameters on the fault impedance still dominates, but the role of the ground resistance is smaller because the shunt current is lower. The multi-region cooperation mechanism of the operating impedance circle successfully avoids the protection blind zone during cross-region faults and improves the overall operating reliability. Although the fault resistance value is lower than that of the single-phase fault, through the dynamic correction of the impedance circle, the distance estimation deviation is still controlled within a reasonable range.

[0149] In one embodiment, the schematic diagram of the change from the old operating impedance circle to the new operating impedance circle is as Figure 13 shown.

[0150] The simulation results show that the dynamic characteristics of the arc and the distribution of line impedance have a significant impact on the performance of the relay. Through the logical optimization of the operating impedance circle, the positioning accuracy and operating reliability of the relay can be significantly improved in complex fault scenarios. Dynamically adjust the impedance circle boundary to adapt to different arc parameters and grounding conditions; enhance the robustness of the protection system through multi-region collaborative design; combine the real-time correction of the arc model to reduce the interference of non-linear characteristics on the determination. It provides theoretical support for optimizing the protection algorithm and verifies the applicability of the model under different fault types and locations.

[0151] As can be seen from the above description, the method for improving the performance of the impedance relay provided in this application constructs an arc model according to the dynamic characteristics of the fault arc when a grounding fault occurs in the power grid; calculates the fault impedance according to the grounding fault type of the fault arc, the electrical parameters at the phase source after the fault, and the arc model; determines the action threshold for performing the open-circuit process according to the arc model; and enables the impedance relay to perform distance protection on the power grid according to the action threshold and the fault impedance, achieving the improvement of the accuracy of the impedance relay in sensing and calculating the fault impedance, improving the modeling and estimation accuracy of the arc resistance, and highlighting the importance of the impedance relay in detecting and locating faults in high-voltage power networks. In addition, this application simulates two types of faults and calculates the arc resistance, providing valuable technical basis for the performance of the impedance relay under different configurations. Based on the above technical basis, the high-voltage power network can be better protected from the threat of fault arcs.

[0152] Based on the same inventive concept, the embodiment of this application also provides an apparatus for improving the performance of an impedance relay, which can be used to implement the method described in the above embodiment, as described in the following embodiment. Since the principle of the apparatus for improving the performance of the impedance relay to solve the problem is similar to that of the method for improving the performance of the impedance relay, the implementation of the apparatus for improving the performance of the impedance relay can refer to the implementation of the method for determining the software performance benchmark, and the repeated parts will not be described again. As used hereinafter, the term "unit" or "module" can be a combination of software and / or hardware that can achieve a predetermined function. Although the systems described in the following embodiments are preferably implemented in software, implementation in hardware, or a combination of software and hardware is also possible and contemplated.

[0153] Figure 6 is a schematic structural diagram of an apparatus for improving the performance of an impedance relay provided by an embodiment of this application, as Figure 6 shown, the apparatus includes:

[0154] An arc model construction unit 601, configured to construct an arc model according to the dynamic characteristics of the fault arc when a grounding fault occurs in the power grid;

[0155] Specifically, when a ground fault occurs, by real-time monitoring the dynamic characteristics of the arc, the arc model construction unit 601 uses the arc conductivity differential equation to describe the evolution of arc conductivity, differentiates the main arc stage in the initial stage of the fault (where the arc length and time constant are basically constant) and the secondary arc stage during the continuous period of the fault (where the arc length linearly increases with time and the time constant gradually decreases), thereby constructing a model that reflects the change characteristics of the arc additional impedance.

[0156] The fault impedance calculation unit 602 is configured to calculate the fault impedance according to the ground fault type of the fault arc, the electrical parameters at the phase source after the fault, and the arc model.

[0157] Specifically, based on the constructed arc model, the fault impedance calculation unit 602 combines the ground fault type corresponding to the fault arc and the electrical parameters measured at the phase source after the fault, and uses a modified impedance calculation formula for calculation. The arc model provides compensation information for the arc additional impedance, making the calculated fault impedance closer to the actual line impedance, thereby more accurately reflecting the location of the fault point.

[0158] The action threshold determination unit 603 is configured to determine the action threshold value for performing the open circuit process according to the arc model.

[0159] Specifically, the action threshold determination unit 603 dynamically adjusts the action threshold value of the relay's open circuit process by using the arc additional impedance information extracted from the arc model. By compensating and matching the initial threshold value with the arc additional impedance, it ensures that when the relay operates, it can effectively filter the errors caused by the arc effect and accurately respond to the real fault impedance, thereby improving the selectivity and reliability of the protection.

[0160] The distance protection execution unit 604 is configured to perform distance protection on the power grid by the impedance relay according to the action threshold value and the fault impedance.

[0161] Specifically, the distance protection execution unit 604 compares the fault impedance corrected by the arc model with the adjusted action threshold value. When the corrected fault impedance is lower than the action threshold value, that is, Z′ F <Z, the impedance relay triggers the open circuit process to achieve distance protection of the power grid, ensuring that when a fault occurs, the impedance relay can quickly and accurately perform protection actions based on the actual fault distance.

[0162] Figure 7 is a schematic structural diagram of an impedance relay performance improvement device provided by an embodiment of the present application. On the basis of the Figure 6 embodiment, further, as Figure 7 shown, the impedance relay performance improvement device provided by the present application further includes:

[0163] The main arc model determination module 701 is configured to determine the main arc model according to the characteristic arc voltage gradient, the total characteristic arc resistance, and the instantaneous arc length when a ground fault occurs in the power grid;

[0164] The secondary arc model determination module 702 is configured to determine the secondary arc model according to the arc elongation speed, the initial time constant, and the time constant decay speed when a ground fault occurs in the power grid.

[0165] Figure 8 It is a schematic structural diagram of an impedance relay performance improvement device provided by an embodiment of the present application. On the basis of the Figure 6 embodiment, further, as Figure 8 shown, the impedance relay performance improvement device provided by the present application further includes:

[0166] The first additional impedance generation module 801 is configured to generate an arc additional impedance according to the arc model;

[0167] The first fault current calculation module 802 is configured to calculate a first fault current according to the grounding coefficient and the current at the post-fault phase source;

[0168] The first fault impedance calculation module 803 is configured to calculate the fault impedance when the single-phase ground fault occurs according to the first fault current, the voltage at the post-fault phase source, and the arc additional impedance.

[0169] Figure 9 It is a schematic structural diagram of an impedance relay performance improvement device provided by an embodiment of the present application. On the basis of the Figure 6 embodiment, further, as Figure 9 shown, the impedance relay performance improvement device provided by the present application further includes:

[0170] The second additional impedance generation module 901 is configured to generate an arc additional impedance according to the arc model;

[0171] The second fault current calculation module 902 is configured to calculate a second fault current according to the current at the post-fault phase source;

[0172] The second fault impedance calculation module 903 is configured to calculate the fault impedance when the double-phase ground fault occurs according to the second fault current, the voltage at the post-fault phase source, and the arc additional impedance.

[0173] Figure 10 It is a schematic structural diagram of an impedance relay performance improvement device provided by an embodiment of the present application. On the basis of the Figure 6 embodiment, further, as Figure 10 shown, the impedance relay performance improvement device provided by the present application further includes:

[0174] An initial threshold value acquisition module 1001 is configured to acquire an initial operation threshold value based on the dynamic characteristics of an electric arc.

[0175] An operation threshold value determination module 1002 is configured to adjust the initial operation threshold value according to the electric arc model to obtain an operation threshold value for the impedance relay to perform a breaking process.

[0176] As can be seen from the above description, the method and device for improving the performance of an impedance relay provided in this application construct an electric arc model according to the dynamic characteristics of a fault electric arc when a grounding fault occurs in a power grid; calculate a fault impedance according to the grounding fault type of the fault electric arc, the electrical parameters at the phase source after the fault, and the electric arc model; determine an operation threshold value for performing a breaking process according to the electric arc model; and perform distance protection on the power grid by the impedance relay according to the operation threshold value and the fault impedance, thereby achieving the improvement of the accuracy of the impedance relay in sensing and calculating the fault impedance, improving the modeling and estimation accuracy of the arc resistance, and highlighting the importance of the impedance relay in detecting and locating faults in a high-voltage power network. In addition, this application simulates two types of faults and calculates the arc resistance, providing valuable technical basis for the performance of the impedance relay under different configurations. Based on the above technical basis, the high-voltage power network can be better protected from the threat of fault electric arcs.

[0177] From a hardware perspective, in order to be able to determine the operation threshold value for the impedance relay to perform a breaking process and improve the performance of the impedance relay, this application provides an embodiment of an electronic device for implementing all or part of the content in the method for improving the performance of the impedance relay. The electronic device specifically includes the following:

[0178] A processor, a memory, a communication interface, and a bus; wherein, the processor, the memory, and the communication interface complete communication with each other through the bus; the communication interface is used to implement information transmission between the device for improving the performance of the impedance relay and related devices such as a core business system, a user terminal, and a related database. The logic controller can be a desktop computer, a tablet computer, a mobile terminal, etc., and this embodiment is not limited thereto. In this embodiment, the logic controller can be implemented with reference to the embodiments of the method for improving the performance of the impedance relay and the embodiments of the device for improving the performance of the impedance relay, and the content thereof is incorporated herein, and the repeated parts will not be elaborated.

[0179] It can be understood that the user terminal may include a smart phone, a tablet electronic device, a network set-top box, a portable computer, a desktop computer, a personal digital assistant (PDA), a vehicle-mounted device, a smart wearable device, etc. Among them, the smart wearable device may include smart glasses, a smart watch, a smart bracelet, etc.

[0180] In practical applications, part of the impedance relay performance improvement method may be executed on the electronic device side as described above, or all operations may be completed in the client device. Specifically, it can be selected according to the processing capacity of the client device and the limitations of the user usage scenario, etc. This application does not make a limitation in this regard. If all operations are completed in the client device, the client device may further include a processor.

[0181] The above-mentioned client device may have a communication module (i.e., a communication unit), and may be communicatively connected to a remote server to implement data transmission with the server. The server may include a server on the task scheduling center side, and may also include a server of an intermediate platform in other implementation scenarios, such as a server of a third-party server platform communicatively linked to the task scheduling center server. The server may include a single computer device, or may include a server cluster composed of multiple servers, or a server structure of a distributed device.

[0182] Figure 11 It is a schematic block diagram of the system composition of the electronic device 9600 according to an embodiment of the present application. As Figure 11 shown, the electronic device 9600 may include a central processing unit 9100 and a memory 9140; the memory 9140 is coupled to the central processing unit 9100. It should be noted that this Figure 11 is exemplary; other types of structures may also be used to supplement or replace this structure to implement telecommunication functions or other functions.

[0183] In one embodiment, the impedance relay performance improvement method function may be integrated into the central processing unit 9100.

[0184] Among them, the central processing unit 9100 may be configured to perform the following controls:

[0185] S101: When a grounding fault occurs in the power grid, construct an arc model according to the dynamic characteristics of the fault arc;

[0186] S102: Calculate the fault impedance according to the grounding fault type of the fault arc, the electrical parameters at the phase source after the fault, and the arc model;

[0187] S103: Determine the action threshold value for performing the open circuit process according to the arc model;

[0188] S104: According to the action threshold value and the fault impedance, the impedance relay performs distance protection on the power grid.

[0189] As can be seen from the above description, the method and device for improving the performance of an impedance relay based on an arc fault model provided by this application improve the accuracy of the impedance relay in perceiving and calculating the fault impedance, improve the accuracy of modeling and estimating the arc resistance, and highlight the importance of the impedance relay in detecting and locating faults in a high-voltage power network. Simulations of two types of faults were carried out, and the arc resistance was calculated, providing valuable technical basis for the performance of the impedance relay under different configurations. Based on the above technical basis, the high-voltage power network can be better protected from the threat of fault arcs.

[0190] In another embodiment, the impedance relay performance improvement device can be separately configured from the central processing unit 9100. For example, the data composite transmission device impedance relay performance improvement device can be configured as a chip connected to the central processing unit 9100, and the functions of the impedance relay performance improvement method are realized through the control of the central processing unit.

[0191] As Figure 11 shown, the electronic device 9600 may further include: a communication module 9110, an input unit 9120, an audio processor 9130, a display 9160, and a power supply 9170. It should be noted that the electronic device 9600 does not necessarily have to include Figure 11 all the components shown in Figure 11 ; in addition, the electronic device 9600 may further include

[0192] As Figure 11 shown, the central processing unit 9100 is sometimes also called a controller or an operation control, and may include a microprocessor or other processor devices and / or logic devices. The central processing unit 9100 receives inputs and controls the operations of the various components of the electronic device 9600.

[0193] Among them, the memory 9140 can be, for example, one or more of a buffer, a flash memory, a hard drive, a removable medium, a volatile memory, a non-volatile memory, or other suitable devices. The above information related to failures can be stored, and in addition, programs for executing relevant information can also be stored. And the central processing unit 9100 can execute the program stored in the memory 9140 to implement information storage or processing, etc.

[0194] The input unit 9120 provides input to the central processing unit 9100. The input unit 9120 is, for example, a button or a touch input device. The power supply 9170 is used to supply power to the electronic device 9600. The display 9160 is used to display display objects such as images and texts. The display can be, for example, an LCD display, but is not limited thereto.

[0195] The memory 9140 can be a solid-state memory, for example, a read-only memory (ROM), a random access memory (RAM), a SIM card, etc. It can also be such a memory that stores information even when powered off, can be selectively erased and has more data stored, and an example of this memory is sometimes referred to as an EPROM, etc. The memory 9140 can also be some other type of device. The memory 9140 includes a buffer memory 9141 (sometimes referred to as a buffer). The memory 9140 can include an application / function storage unit 9142, which is used to store application programs and function programs or the processes for operating the electronic device 9600 through the central processing unit 9100.

[0196] The memory 9140 can also include a data storage unit 9143, which is used to store data, such as contacts, digital data, pictures, sounds, and / or any other data used by the electronic device. The driver storage unit 9144 of the memory 9140 can include various drivers of the electronic device for communication functions and / or for performing other functions of the electronic device (such as a messaging application, an address book application, etc.).

[0197] The communication module 9110 is a transmitter / receiver 9110 that transmits and receives signals via the antenna 9111. The communication module (transmitter / receiver) 9110 is coupled to the central processing unit 9100 to provide input signals and receive output signals, which can be the same as in the case of a conventional mobile communication terminal.

[0198] Based on different communication technologies, multiple communication modules 9110 can be provided in the same electronic device, such as a cellular network module, a Bluetooth module, and / or a wireless local area network module, etc. The communication module (transmitter / receiver) 9110 is also coupled to the speaker 9131 and the microphone 9132 via the audio processor 9130 to provide an audio output via the speaker 9131 and receive an audio input from the microphone 9132, so as to implement the usual telecommunications functions. The audio processor 9130 can include any suitable buffer, decoder, amplifier, etc. In addition, the audio processor 9130 is also coupled to the central processing unit 9100, so that it is possible to record on the device through the microphone 9132 and play the sound stored on the device through the speaker 9131.

[0199] An embodiment of the present application further provides a computer-readable storage medium capable of implementing all steps of the impedance relay performance improvement method with the execution subject being a server or a client in the above embodiments. A computer program is stored on the computer-readable storage medium. When the computer program is executed by a processor, all steps of the impedance relay performance improvement method with the execution subject being a server or a client in the above embodiments are implemented. For example, when the processor executes the computer program, the following steps are implemented:

[0200] S101: When a grounding fault occurs in the power grid, construct an arc model according to the dynamic characteristics of the fault arc;

[0201] S102: Calculate the fault impedance according to the grounding fault type of the fault arc, the electrical parameters at the phase source after the fault, and the arc model;

[0202] S103: Determine the action threshold value for performing the open-circuit processing according to the arc model;

[0203] S104: Perform distance protection on the power grid by the impedance relay according to the action threshold value and the fault impedance.

[0204] As can be seen from the above description, the impedance relay performance improvement method and device provided by the present application improve the accuracy of the impedance relay in perceiving and calculating the fault impedance, improve the modeling and estimation accuracy of the arc resistance, and highlight the importance of the impedance relay in detecting and locating faults in high-voltage power networks. Two types of faults are simulated, and the arc resistance is calculated, providing valuable technical basis for the performance of the impedance relay under different configurations. Based on the above technical basis, the high-voltage power network can be better protected from the threat of fault arcs.

[0205] Those skilled in the art should understand that the embodiments of the present invention can be provided as a method, a device, or a computer program product. Therefore, the present invention can take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware aspects. Moreover, the present invention can take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0206] The present invention is described with reference to the flowcharts and / or block diagrams of methods, apparatuses (devices), and computer program products according to embodiments of the present invention. It should be understood that each flow and / or block in the flowcharts and / or block diagrams, as well as the combination of flows and / or blocks in the flowcharts and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to the processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing devices to generate a machine, such that the instructions executed by the processor of the computer or other programmable data processing devices generate means for implementing the functions specified in one or more flows and / or blocks. Figure 1 in one or more flows and / or blocks Figure 1 or in one or more blocks.

[0207] These computer program instructions can also be stored in a computer-readable memory that can direct a computer or other programmable data processing device to work in a specific manner, such that the instructions stored in the computer-readable memory generate a manufactured article including instruction means that implement the functions specified in one or more flows and / or blocks. Figure 1 in one or more flows and / or blocks Figure 1 or in one or more blocks.

[0208] These computer program instructions can also be loaded onto a computer or other programmable data processing device, such that a series of operational steps are executed on the computer or other programmable device to generate a computer-implemented process, and thus the instructions executed on the computer or other programmable device provide steps for implementing the functions specified in one or more flows and / or blocks. Figure 1 in one or more flows and / or blocks Figure 1 or in one or more blocks.

[0209] Specific embodiments are applied in the present invention to elaborate on the principles and implementation manners of the present invention. The description of the above embodiments is only used to help understand the method and its core idea of the present invention; at the same time, for those of ordinary skill in the art, according to the idea of the present invention, there will be changes in the specific implementation manners and application scopes. In summary, the content of this specification should not be construed as a limitation to the present invention.

Claims

1. A method for improving the performance of an impedance relay, characterized in that: include: When a ground fault occurs in the power grid, an arc model is constructed based on the dynamic characteristics of the fault arc; Calculating the fault impedance according to the ground fault type of the fault arc, the electrical parameters at the phase source after the fault, and the arc model; Determine an action threshold value for executing circuit breaking processing according to the arc model; The impedance relay performs distance protection on the power grid according to the action threshold value and the fault impedance.

2. The method for improving the performance of an impedance relay according to claim 1, characterized in that: The arc model includes a primary arc model and a secondary arc model; When a ground fault occurs in the power grid, an arc model is constructed according to the dynamic characteristics of the fault arc, including: Determining the main arc model according to the characteristic arc voltage gradient, the total characteristic arc resistance and the instantaneous arc length when a ground fault occurs in the power grid; The secondary arc model is determined according to the arc extension speed, the initial time constant and the time constant decrease speed when a ground fault occurs in the power grid.

3. The method for improving the performance of an impedance relay according to claim 1, characterized in that: The ground fault type includes a single-phase ground fault; the electrical parameters include a current at a phase source after the fault, a voltage at a phase source after the fault, and a grounding coefficient; The calculating of the fault impedance according to the ground fault type of the fault arc, the electrical parameters at the phase source after the fault and the arc model includes: generating an arc additional impedance according to the arc model; Calculate a first fault current according to the grounding coefficient and the current at the phase source after the fault; The fault impedance when the single-phase grounding fault occurs is calculated according to the first fault current, the voltage at the phase source after the fault, and the arc additional impedance.

4. The method for improving the performance of an impedance relay according to claim 1, characterized in that: The ground fault type includes a double-phase ground fault; the electrical parameters include a current at a phase source after the fault and a voltage at a phase source after the fault; The calculating of the fault impedance according to the ground fault type of the fault arc, the electrical parameters at the phase source after the fault and the arc model includes: generating an arc additional impedance according to the arc model; Calculating a second fault current according to the current at the phase source after the fault; The fault impedance when the double-phase grounding fault occurs is calculated according to the second fault current, the voltage at the phase source after the fault, and the arc additional impedance.

5. The method for improving the performance of an impedance relay according to claim 1, characterized in that: The step of determining the action threshold value for the impedance relay to perform circuit breaking processing according to the arc model and the fault impedance includes: Obtaining the initial action threshold value based on the dynamic characteristics of the arc; The initial action threshold value is adjusted according to the arc model to obtain the action threshold value for the impedance relay to perform circuit breaking processing.

6. A device for improving the performance of an impedance relay, characterized in that: include: An arc model building unit, used for building an arc model according to the dynamic characteristics of the fault arc when a ground fault occurs in the power grid; A fault impedance calculation unit, used for calculating the fault impedance according to the ground fault type of the fault arc, the electrical parameters at the phase source after the fault and the arc model; an action threshold determination unit, configured to determine an action threshold value for executing a circuit breaking process according to the arc model; The distance protection execution unit is used to enable the impedance relay to perform distance protection on the power grid according to the action threshold value and the fault impedance.

7. The device for improving the performance of an impedance relay according to claim 6, characterized in that: The arc model includes a primary arc model and a secondary arc model; The arc model building unit comprises: A main arc model determination module, used to determine the main arc model according to a characteristic arc voltage gradient, a total characteristic arc resistance and an instantaneous arc length when a ground fault occurs in the power grid; The secondary arc model determination module is used to determine the secondary arc model according to the arc extension speed, the initial time constant and the time constant decrease speed when a ground fault occurs in the power grid.

8. The device for improving the performance of an impedance relay according to claim 6, characterized in that: The ground fault type includes a single-phase ground fault; the electrical parameters include a current at a phase source after the fault, a voltage at a phase source after the fault, and a grounding coefficient; The fault impedance calculation unit comprises: A first additional impedance generating module, configured to generate an arc additional impedance according to the arc model; A first fault current calculation module, used for calculating a first fault current according to the grounding coefficient and the current at the phase source after the fault; The first fault impedance calculation module is used to calculate the fault impedance when the single-phase grounding fault occurs according to the first fault current, the voltage at the phase source after the fault, and the arc additional impedance.

9. The device for improving the performance of an impedance relay according to claim 6, characterized in that: The ground fault type includes a double-phase ground fault; the electrical parameters include a current at a phase source after the fault and a voltage at a phase source after the fault; The fault impedance calculation unit comprises: A second additional impedance generating module, configured to generate an arc additional impedance according to the arc model; A second fault current calculation module, used for calculating a second fault current according to the current at the phase source after the fault; The second fault impedance calculation module is used to calculate the fault impedance when the double-phase grounding fault occurs according to the second fault current, the voltage at the phase source after the fault and the arc additional impedance.

10. The device for improving the performance of an impedance relay according to claim 6, characterized in that: The action threshold determination unit comprises: An initial threshold value acquisition module is used to obtain an initial action threshold value based on the dynamic characteristics of the arc; The action threshold value determination module is used to adjust the initial action threshold value according to the arc model to obtain the action threshold value for the impedance relay to perform circuit breaking processing.

11. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that: When the processor executes the program, the steps of the impedance relay performance improvement method according to any one of claims 1 to 5 are implemented.

12. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the impedance relay performance improvement method according to any one of claims 1 to 5 are implemented.

13. A computer program product comprising a computer program / instructions, characterized in that When the computer program / instruction is executed by a processor, the steps of the method for improving the performance of an impedance relay as described in any one of claims 1 to 5 are implemented.

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